Sydney Markets has undergone remarkable transformation since its humble beginnings over 200 years ago on the wharves of Sydney.
Today, Sydney Markets is recognised internationally for its world-class fresh produce and community markets, it is the largest fresh fruit and vegetable wholesale market in Australia and one of the largest in the world. Sydney Markets is now also home to the largest ‘behind-the-meter’ solar power system in NSW and the largest solar PV system in Sydney.
Autonomous Energy has designed, built, operated and maintained this 3.2MW system, rolled out across four separate phases. The first three phases were solar carpark shading systems and the fourth phase is a 2.2MW roof parallel system. Interestingly, there was a lot more to phase four than simply installing 2.2MWs of solar equipment. Before integrating the solar modules, Autonomous Energy installed a special roof membrane to prevent any small leaks as the roofs are over 40 years old. The membrane was also a highly reflective white colour, which when combined with the installation of the solar modules, significantly reduces the thermal load on the building, which is important from an energy efficiency perspective as one of the buildings contains mostly refrigerated cool rooms. Over 3kms of permanent walkways and handrails were installed to ensure safe access to all solar panels as well as edge protection – this was completed prior to the installation of the solar arrays, to minimise the risk of roof damage during installation and maximise safety for Autonomous Energy’s installation team. New hose reels were installed along each roof ensuring that every panel can be reached by a hose for effective cleaning.
To accurately mark out the whole system, Autonomous Energy had each roof surveyed by a qualified surveyor prior to the installation. This ensured that the installation accurately matched the design over a large roof area (approximately 2 hectares). Laser devices and triangulation methods were used to ensure best practice in alignment of all solar modules (rows were up to 260m long). All craning locations were examined by structural engineers and certifications were provided before craning commenced, ensuring best practice in safety management. Strict Inspection Test Plans (ITPs) were maintained throughout the project and signed off by the Project Manager and Site Manager at critical points. Each array had a designated, CEC accredited Quality Control Officer, ensuring best practice quality management. Over 8000 super high efficiency LG NeON solar modules were integrated across phases two, three and four, with phase one using Japanese made Kyocera modules. Phase four utilises panel level optimisation (SolarEdge Technology) to maximise the performance of each module whilst ensuring the safest possible system from a DC electricity point of view.
There were a number of site specific technical challenges that needed to be overcome by Autonomous Energy’s engineering and construction teams, including:
- Connecting the output of the systems to the existing Main Switch Boards (MSBs) at each building which were more than 40 years old, with original switchgear and no room for additional circuit breakers, so Autonomous needed to devise a solution. For Building D this consisted of a major MSB modification, incorporating the two new solar circuits with two existing circuits into a new cubicle, added to the end of the existing switchboard. The new cubicle was designed with sufficient segregation to allow installation in two stages, with only one shutdown. The new cubicle was installed and the connection to the existing bus bars completed. The new solar circuit breaker was then isolated and locked off, with the connection point for the submains from the inverter switchboard in a physically separate compartment. These were then terminated at a later date using the new circuit breakers for isolation rather than requiring isolation at the transformer.
- For Building E, there was no space in the main switch room to install additional switchboard cubicles so the solution was to install two new switchboards in the plant room where the inverters were located. These new boards were fed from existing submains, run from the main switch room. These submains were insufficient for the current rating of the solar, so one set of submains was replaced altogether and the other upgraded with additional parallel circuits to a new 1250A “take off box” which allowed the submains to then feed the solar and existing services while maintaining compliance with AS3000.
- Shutdowns required at various stages to allow for switchboard modifications, cable upgrades and connections had a strict maximum time limit, due to the quantity of refrigerated loads on site. Shutdowns were coordinated with site users, specialised contractors and the client to ensure minimal disruption and all were executed seamlessly. At stake for example was all of Sydney’s supply of fresh bananas, worth several millions of dollars.
- The existing transformers (which feed the buildings to which the solar is connected and are part of the client’s internal high voltage infrastructure) are approximately 40 years old. There was concern that back-feeding solar could cause damage, so in coordination with the transformer manufacturer, Autonomous Energy undertook power quality monitoring of each transformer and installed harmonic filters to protect against the worst-case harmonic levels that could be generated by the inverters.
Martin Foster, head of site services, Sydney Markets, explained why Autonomous Energy was selected for this complex solar project: “Following our stringent competitive tender process, Autonomous Energy provided the best solution that met our scope and output requirements. The project was delivered to a high standard and high level of quality despite the difficult working environment at the Markets. Autonomous Energy have exceeded our expectations, which has also resulted in a higher return on investment.”
Mark Gadd, managing director at Autonomous Energy says that bigger is not necessarily better when it comes to Solar PV.
“With all the excitement around large solar farms, it’s easy to miss the fact that onsite, behind-the-meter solar PV, provides more value. This is due to the fact that distributed Solar PV, like the Sydney Markets installation, does not rely on expensive transmission and distribution networks and electricity retailers to reach the customer. With additional onsite generation capacity and battery storage added in the future, sites like Sydney Markets have enormous flexibility to interact with the NEM in new and innovative ways including demand response, blackout protection, energy trading and even grid defection.”